In manufacturing processes of a semiconductor device, plasma etching is performed by using a photoresist, in which a pattern is formed using a photolithography technology, as an etching mask, and a circuit pattern is transferred to an object film to be etched by the plasma etching. When a pattern is projected onto the photoresist via photolithography, in the CD of a 45 nm generation, an ArF resist is used as the photoresist to achieve minuteness and an ArF laser beam having a wavelength of 193 nm is used as light to which the ArF resist is exposed.
However, the ArF resist has low plasma resistance. Accordingly, a technology of stacking a SiO2 film and a resist film having high plasma resistance below the ArF resist and patterning by using the multilayer resist film has been suggested.
Also, a technology in which an amorphous carbon film, as a replacement of the SiO2 film or as an anti-reflection layer, formed via a CVD (Chemical Vapor Deposition) process using a hydrocarbon gas and an inert gas is included in the multiplayer resist film(for example, refer to Patent Document 1) has been suggested.
Also, recently, a patterning technology that does not use a photolithography technology in a part of process has been suggested. In detail, for example, a multilayer resist film is formed by stacking an SiO2 film below an ArF resist film, and an amorphous carbon film below the SiO2 film, and the multilayer resist film is patterned as follows. In detail, first, the ArF resist film is patterned, and then the SiO2 film is etched by using the patterned ArF resist film. Then, the amorphous carbon film is etched by using the patterned SiO2 film. As a result, a pattern formed on the ArF resist film may be transferred to the amorphous carbon film without having to use a photolithography technology in processes other than a patterning process of the ArF resist film.
(Patent Document 1) Japanese Laid-Open Patent Publication No. 2002-12972